Mr. Holder called our current system “broken,” and he couldn’t be more right. Congress needs to consider and pass my bipartisan legislation to provide flexibility for federal judges in sentencing nonviolent offenders, which I have introduced with Senate Judiciary Committee Chairman Patrick J. Leahy, Vermont Democrat.

The United States has the highest incarceration rate in the world. Many of those people deserve to be in prison; however, some of them do not. They find themselves incarcerated owing to a misguided focus on draconian punishment that does nothing to enhance public safety. As Mr. Holder noted, incarceration rates have grown “at an astonishing rate — by almost 800 percent” since 1980.

Almost half of these inmates are serving time for drug-related crimes.

Many of them find themselves in prison sometimes for making one nonviolent mistake — for decades or more — because our federal government mandates it. Throughout the 1970s, ‘80s and ‘90s, federal mandatory minimum laws were implemented that forced judges to deliver sentences far lengthier than they would have if allowed to use their own discretion. The result has been decades of damage, particularly to young people.

We have all made mistakes in our youth, but we shouldn’t ruin people’s entire lives for making youthful mistakes. By today’s legal standards, the past two presidents could have been imprisoned for decades as punishment for alleged indiscretions in their youth.

These laws are so unrealistic that sometimes the young person convicted didn’t even knowingly make a mistake. The Associated Press reported this week: “Former federal appeals court Judge Timothy Lewis recalled that he once had to sentence a 19-year-old to 10 years in prison for conspiracy for being in a car where drugs were found.” The report continued: “Lewis, a former prosecutor, said the teen, who was [black], was on course to be the first person in his family to go to college. Instead, Lewis had to send him to prison as the teen turned and screamed for his mother.”

Judge Lewis’ hands were tied as he was forced to severely punish this young man. Said Judge Lewis after Mr. Holder’s announcement, “I am just glad that someone finally has the guts to stand up and do something about what is a pervasively racist policy.”

Mandatory minimum sentencing has disproportionately affected blacks, Hispanics and others who often don’t have the financial means to fight back. In so many of these cases, federal laws make it impossible for well-meaning judges, law enforcement and families to do anything to reverse these bad decisions.

Drug abuse is no doubt destructive to families and society, but mandatory minimum laws often do far more damage to families and society than the problems they were intended to fix.

Timothy Tyler is another victim of these laws. In 1994, Timothy was a “deadhead” with prior infractions that had resulted in probation. He was sentenced to life in prison for selling LSD to a police informant.

Tyler should have been punished for selling drugs, but he shouldn’t have to spend the rest of his life in prison for it. Today, Timothy is 45 and will likely spend the rest of his life behind bars, not because a judge thought it was a proper punishment, but because an arbitrary federal law demanded it.

The president and founder of Families Against Mandatory Minimums, Julie Stewart, told Business Insider: “He was a kid. He was following the Grateful Dead. I’m not condoning it, but it was a pretty harmless lifestyle Timothy was leading.” Ms. Stewart added, “It always seemed really absurd to me that for this nonviolent guy who was 24 years old, the government could write off his life. Bingo. You’re gone.” There are rapists and murderers who are given more lenient sentences than what Tyler received.

Nonviolent offenders don’t always return to society as normal and productive citizens after serving hard time alongside rapists and murderers. Those who are released after decades of imprisonment often have trouble finding employment and suffer from a host of other problems related to their history.

This is not proper justice — and it must end.

I look forward to working with the White House to advance my Justice Safety Valve Act (S. 619), which would permanently restore justice by preserving judicial discretion in federal cases. I introduced this legislation in March with Mr. Leahy as a bipartisan legislative fix to the very problem Mr. Holder now addresses.

We must work hard in a bipartisan fashion to change these laws. Mandatory minimum sentencing has already done enough damage to enough Americans. Judges can determine fair justice far better than any inane federal mandate.

It is now our responsibility to work together to protect the next generation from this madness.

Sen. Rand Paul, Kentucky Republican, is a member of the Senate Foreign Relations and Homeland Security committees.